The present invention pertains to a method of verification of a decoding and enabling arrangement and more particularly to a method for diagnosing a unique addressing arrangement.
Modern microprocessors are applied to a number of real time applications which involve the controlling and sensing of external devices. These microprocessors need to control a number of distinct events. Control points and sense points provide this function of interfacing microprocessor to such real time tasks as telecommunication systems. Since telecommunications systems provide their services for many thousands of people, great numbers of sense points and control points are required for the microprocessors to perform these switching operations.
These control points and sense points must be grouped into manufacturable entities, with which a microprocessor may communicate. The microprocessor must have a scheme which allows for the manipulation of these sense points and control points. To accomplish this function addressing schemes are commonly employed. These addressing schemes requires decoding addresses supplied by the microprocessor in order to operate each one of these sense and control points.
Verifying the integrity of the operation of these control and sense points is essential to the efficient operation of a modern telecommunications system.
The GTD-5-EAX, which employs the present invention, utilizes a unique bussing arrangement for communicating with these control points and sense points. Diagnosing faults in a bussing arrangement is typically accomplished by repeated access to the equipment setting a particular bit and verifying that this particular bit is returned to the microprocessor. This set bit (logic 1) is placed (stepped through) each of the possible bit positions in order to verify the operation of the control points and sense points. GTD-5-EAX is a central office telecommunications product manufactured by GTE Communications Systems Incorporated.
The traditional bit stepping approach is not effective to diagnose faults in the control points and sense points of the GTD5-EAX, because of its unique bussing arrangement.